Bioassay monitoring is an important capability for any facility that works with significant amounts of radioactive material. The speed at which these analyses can be made is critical in the event of ...a potential exposure. In this study, we present a new method that facilitates the rapid separation of uranium from a urine matrix for assay and isotopic determination by inductively coupled plasma mass spectrometry. This method is validated with archived urine samples that were previously analyzed using established, more time consuming methods. The sources of uncertainty for uranium assay and isotopic measurements are modelled using the Monte Carlo method to better understand the precision and accuracy of this method at the limit of quantification.
Improved methods employed at Los Alamos National Laboratory for
231
Pa/
235
U radiochronometry are outlined. We present elution curves obtained during
233
Pa tracer preparation from
237
Np. ...Additionally, we report model ages for uranium certified reference materials (CRMs) exhibiting a range of
235
U enrichments including the first
231
Pa/
235
U model ages for CRMs U200 and U900. Our results enable these CRMs to be used, with increased confidence, as quality control materials during nuclear forensics investigations.
Improved methods employed at Los Alamos National Laboratory for .sup.231Pa/.sup.235U radiochronometry are outlined. We present elution curves obtained during .sup.233Pa tracer preparation from ....sup.237Np. Additionally, we report model ages for uranium certified reference materials (CRMs) exhibiting a range of .sup.235U enrichments including the first .sup.231Pa/.sup.235U model ages for CRMs U200 and U900. Our results enable these CRMs to be used, with increased confidence, as quality control materials during nuclear forensics investigations.
Atherothrombosis is the leading cause of cardiovascular morbidity and mortality around the globe. To date, no single international database has characterized the atherosclerosis risk factor profile ...or treatment intensity of individuals with atherothrombosis.
To determine whether atherosclerosis risk factor prevalence and treatment would demonstrate comparable patterns in many countries around the world.
The Reduction of Atherothrombosis for Continued Health (REACH) Registry collected data on atherosclerosis risk factors and treatment. A total of 67,888 patients aged 45 years or older from 5473 physician practices in 44 countries had either established arterial disease (coronary artery disease CAD, n = 40,258; cerebrovascular disease, n = 18,843; peripheral arterial disease, n = 8273) or 3 or more risk factors for atherothrombosis (n = 12,389) between 2003 and 2004.
Baseline prevalence of atherosclerosis risk factors, medication use, and degree of risk factor control.
Atherothrombotic patients throughout the world had similar risk factor profiles: a high proportion with hypertension (81.8%), hypercholesterolemia (72.4%), and diabetes (44.3%). The prevalence of overweight (39.8%), obesity (26.6%), and morbid obesity (3.6%) were similar in most geographic locales, but was highest in North America (overweight: 37.1%, obese: 36.5%, and morbidly obese: 5.8%; P<.001 vs other regions). Patients were generally undertreated with statins (69.4% overall; range: 56.4% for cerebrovascular disease to 76.2% for CAD), antiplatelet agents (78.6% overall; range: 53.9% for > or =3 risk factors to 85.6% for CAD), and other evidence-based risk reduction therapies. Current tobacco use in patients with established vascular disease was substantial (14.4%). Undertreated hypertension (50.0% with elevated blood pressure at baseline), undiagnosed hyperglycemia (4.9%), and impaired fasting glucose (36.5% in those not known to be diabetic) were common. Among those with symptomatic atherothrombosis, 15.9% had symptomatic polyvascular disease.
This large, international, contemporary database shows that classic cardiovascular risk factors are consistent and common but are largely undertreated and undercontrolled in many regions of the world.
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